<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.1.3/vue.js"></script>
</head>
<body>

<script>
    let MyMyPlugin ={};
    MyMyPlugin.install = function(Vue,options){
        Vue.test = function() {
            console.log('plingin test')
        }
    };
    Vue.use(MyMyPlugin);
    let vm = new Vue({
        created:function() {

        }
    })
    vm.test()
</script>

</body>
</html>